Historically, farmers have harvested ensilage crops from their fields and stored the harvested ensilage in large storage units. The harvesting procedure generally entails field chopping the ensilage and blowing or dumping the chopped ensilage into a storage unit such as vertical silos, pit or trench silos. In the case of open trench or pit silos, the ensilage is typically confined between two parallel walls open at one or sometimes both ends. The open ends afford mechanical access for removing the ensilage from the pit or trench. Tractors or skid steer loaders equipped with forked buckets are frequently used to remove compacted ensilage from these pit or trench silos. The current mechanical techniques for removing the ensilage is ineffective and often leads to substantial ensilage spoilage and waste.
Ensilage spoilage and waste is largely due to the ineffectiveness of current equipment in removing only what ensilage is needed while preserving the anaerobic and compacted character of the stored ensilage. As part of the harvesting and storing operations, the ensilage weight compacts the loosely chopped ensilage product into a dense, compacted ensilage mass. The loose and free flowing ensilage stems of the freshly harvested product become extensively intertwined within the mass and thus tenaciously hold the ensilage mass together in a dense, compacted ensilage product. Compacted ensilage of legumous cropping is most difficult to remove from open pits or trench silos since the intertwined stemmings tenaciously bind the ensilage together as a solid and compacted mass. The resultant compacted ensilage cannot be easily removed manually with a conventional manual or mechanical silage fork equipment. The technique of removing the compacted silage from the storage unit typically involves tearing and removing a compacted segment of the silage from the silo or pit.
Preservation of the ensilage in an unspoiled state necessitates maintaining anaerobic conditions. Excessive exposure to air accelerates spoilage. The most common method for removing ensilage from a trench silo (by driving a forked or bucket loader into the trench and lifting or pulling a torn top layer of compacted silage from the silo or pit) fails to preserve the anaerobic conditions. The tearing of intertwined stemmings from the compacted ensilage mass creates a highly irregular, creviced and porous surface. The irregular and porous surface increases the total exposed surface area to air which in turn renders the exposed ensilage susceptible to oxidative deterioration and increased spoilage.
Heretofore, a trench silo unloader known to the trade as a FOX 618 Trench Silo Unloader had been specially made for use in removing ensilage from trench silos. The unloader was relatively effective when used in trench silos filled with corn ensilage. Corn ensilage is, however, easier to remove since it is not as densely intertwined and compacted is as the case for legumous ensilage. The FOX unloader was adapted for a three-point hookup onto relatively large farm tractors. The unloader included a rotating reel fitted with hooked cutters, an auger and blower assembly for blowing the removed ensilage, and means for raising and lowering the rotating reel to the appropriate working level. The reel was driven by a power take-off system supplied by the tractor which also supplies power for hydraulically raising or lowering the reel about a support post or column. Although the Fox Trench Silo unloader worked effectively upon corn ensilage products, the device was not effective when used upon the more compacted and intertwined legumous ensilages such as ensilages of pea, alfalfa, clover, soy beans, etc. The unloader cutters were of a design for hooking, unevenly tearing and pulling ensilage from the compacted ensilage mass. The hooking and tearing mode of operation, when applied to compacted legumous ensilage, creates an uneven and porous surface highly susceptible to spoilage. It is important in any efficient farming operation, however, for such compacted legumous ensilages to be uniformly cut and evenly removed from the exposed vertical face of a compacted ensilage mass without substantially increasing the exposed surface region or altering the compacted character of the exposed surface or sub-surface ensilage.